Bios reset button vs Jumper reset

Can someone please explain the difference between bios reset button (loads backup bios) and using the jumper reset?

I have used the reset button as my router was completely unresponsive- it booted up again perfectly, all settings there. So I am guessing if you use the jumper it wiped everything.

I am used to commercial routers where you only have one reset option that wiped everything.

Where does the backup BIOS load from? Now that I have done this, will it boot normally net time? Do I have to do anything to boot it not using the backup bios?

What info is stored in bios and what is stored in software/routeros?

Thanks in advance.